Etching machine



W. GUENST ETCHING MACHINE Filed May 27, 1935 3 Shee'its-sheet w. sums-r 2,15%,8

ETCHING MACHINE Plled Mav 27 1535 S Sheets-Sheet 3 Patented Apr. 4, 1939 I UNITED STATES PATENT OFFICE ETCHING MACHINE William Guenst, Philadelphia, Pa. Application May 2'2, 1935, Serial No. 23,598 7 Claims. (01. 299-63) My invention relates to improvements in etchclosed, thereby preventing breakage of the cover ing machines of the rotor type in which rotating or the receptacle.

blades cast a variant spray of etching liquor upon Further purposes will appear in the specificaplates to be etched. tion and in the claims. A purpose of my invention is to construct an I have elected to show one form only of my etching machine in which paddle sections are invention, with a slight modification of a part of placed on a rotatable shaft, each individual blade the construction, selecting a form that is pracof each paddle section being preferably formed tical and efficient in operation and which particby stamping and being detach-able from division ularly well illustrates the principles involved.

A further purpose is to provide tongue and upper portion of my etching machine with the slot connections between individual blades and cover in place against the rubber cushion. division walls of an etching machine paddle. Figure 9 is a fragmentary longitudinal section so A further purpose is to provide an eccentric similar to a portion of Figure 3, but illustrating a block by which the position of the paddle wheel modified form of blade and paddle construction.

shaft is raised or lowered to vary the amount of Figure 10 is a transverse section taken on the etching spray or liquor thrown onto the plates line Ill-Ill of Figure 9.

when the rotary paddle blades dip into the etch- Figure 11 is an enlarged fragmentary section of 33 ing liquor in the machine. the paddle construction of Figures 9 to 11, taken 35 A further purpose is to construct a paddle comon the line I !l I of Figure 10.

prising division walls and a number of individual Like numerals refer to like parts in all figures. blades of longitudinal half circular sectional ma- Describing in illustration and not in limitation terial, resistant to etching liquor, such as Bakeand referring to the drawings:

4;; lite or the like, rotating the half circular blades The present application contains improvements to have their dipping edges register alternately upon a structure of my U. S. Patent No. 1,947,391, nearer or farther away from the paddle wheel dated February 13, 1934. shaft and providing recesses in the division walls The device in the present illustration comprises between each paddle section upon the paddle a receptacle 15 with a bottom wall l6, side walls shaft for permitting the rotation of the half cir- H and front and rear walls l8 and [9 respectively. cular blades and locking or securing the blades in I place liquor for the etching process in the reany desired position. ceptacle. The etching liquor is normally nitric A further purpose is to provide a reinforced acid or ferric chloride solution. The form of rubber cover for etching machines, which cover Figures 1 to 8 is intended for use with nitric acid.

1. has a corrugated rib that tends to keep the cover or a similar etching agent not corrosive to the straight and adds resilience. stainless steel paddle there shown, while the form A further purpose is to construct an etching of Figures 9 to 11 is intended primarily for use machine tank wall with a recess into which a soft with ferric chloride. The receptacle I5 is conrubber cushion is placed and against which the structed of any material which is resistant to the 1() Walls between the paddle sections, and the blades Figure l is a front elevation of an etching 10 being alternately spaced at their outer ends in machine embodying my invention. such a. position that when the rotated blades dip Figure 2 is a side elevation of Figure 1. into the etching liquor, the radially outer blades Figure 3 is a longitudinal section taken on the of each paddle section will dip into the liquor, the line 3-3 of Figure 2. 5 radially inner blades will receive spray dripping Figured is a transverse section taken on the line 15 from beneath a bafile wall in the machine and 4-4 of Figure l. the two sets of blades differently spaced will cause Figure 5 is an end elevation illustrating a detail a very eflicient spray to be thrown by the paddle of the blade and division wall assemblage in the blades onto a plate to be etched. preferred form. go A further purpose is to assemble blades of a Figure 5a is a perspective view of one of the 20 paddle upon a rotatable shaft, by placing individdivision walls of my preferred form of paddle. ual blades between circular division walls, the in- Figure 6 is a transverse section taken on the dividual blades being alternately extended nearer line 6-6 of Figure 5. to or farther from the outer circumference of the Figure '7 is a perspective view of one of the Q5 division walls which are in fixed position upon blades used in my preferred form of paddle. 25 the shaft. Figure 8 is an enlarged fragmentary View of the cover of the machine is contacted when it is action of etching liquor, preferably stoneware or 55 a refractory composition resistant to the etching liquor.

At the front wall l8 of the receptacle 2. baflle wall 20 is placed to extend rearwardly towards the rear wall |9 between the side walls l1 for the full width therebetween.

I arrange transversely through the receptacle and some distance below the baffle wall 20 and parallel thereto, a rotatable shaft 2| having a driving pulley 22 upon which is placed a liquor spreader or paddle which comprises a plurality of paddle sections 23. The sections 23 are formed of a suitable material which is resistant to the action of etching liquor.

In the preferred form, each section 23 of the spreader or paddle constitutes a plurality of blades 24 (preferably four) which are positioned in division walls 25 by means of tongues 26 extending into one or other of two setsof slots 21 and 21' suitably spaced so that when the blades are in proper position with respect to one a other, one blade edge or free end 28 of the blade in the slots-of set 21 is placed nearer to the outer circumference 29 of the division wall 25 than the adjoining blade edge or free end 30 of the blade in the slots of the set 21'. The edges 28 and 3B are placed alternately with respect to one another. It will be noted, however, that each division wall is stamped with slots 3| and 32 nearer the shaft center and at 33 and 34 close to the outer circumference of the division wall.

By utilizing the spacings of the slots in each division wall as described above I can readily assemble the individual blades of the paddle, in alternate positions by placing the tongues 26 of successive blades either in the slots 3| and 33 or in the slots 32 and 34, thereby positively locating the blades in a pre-arranged position with respect to the division walls and paddle shaft.

The division walls are provided with apertures 35 to allow for placement of the individual division walls upon the shaft. As each division wall is moved on the shaft, one set of tongues on one side of one set of blades are inserted into either set of slots in one of the division walls; the corresponding set of tongues on the other side of the blades are inserted into corresponding slots in another division wall; the next set of blades is then placed in the set of slots that have not been used and another division wall is set in place with the tongues. This procedure is followed until a paddle of the desired length is completed.

The blades used in my invention are identical in construction and I have found that the most convenient and economical way to make these blades is by stamping them from metal resistant to etching liquor, such as stainless steel, desirably of the composition 18% chromium, 8% nickel, remainder iron, although I do not wish to limit the invention to the particular construction shown as other material may be desirable in some instances.

As shown in the detail view of Figure 7 each individual blade is bent along lines such as 36 and 31, to provide a scoop end 38, and portions 39 and 40 to form the completed paddle when the blades are assembled against the division walls.

The side walls I 1 of the receptacle are provided with inwardly extending hubs 4| through which openings 42 for the shaft 2| pass. Individual flanges in the present instance are provided by placing washers 43 between sleeve members 44, which sleeve members act as spacers for the washers. The spacer nearest to the end partition walls of the paddle structure holds all of the division plates and all of the blades in place upon the threaded portion of the shaft outside of the receptacle walls.

The interior of each of the hubs 4| integral with the receptacle walls is provided with a plurality of annular grooves 45 spaced adjacent the outer diameter of the washers 43. The interior diameters of the flanges 46 of each opening 41 and the exterior diameters of the washers 43 are the same. This construction serves effectively to prevent any etching liquor from leaving the receptacle through the opening 47 during the etching operation and also permits easy assembling of the parts of the machine by permitting the paddle shaft to be moved easily through the openings 42 from the exterior of the receptacle. Should any etching liquor find its way to the Washers 43 it will be discharged therefrom and into the grooves 45 by centrifugal action and it will then flow by gravity back into the receptacle 5 through drain passages 48 leading from the bottoms of the grooves 45 into the interior of the receptacle.

Beyond the receptacle walls H, the respective end portions 2| of the shaft 2| extend outwardly through and beyond the openings 42 in the side walls I! of the receptacle and they are fitted to rotate in bearings 49 which are secured to pivoted side arms 50 of a frame which comprises the pivoted side arms and a bar 5| connecting the rear ends thereof and secured thereto.

I prefer to provide for adjustability of height of the paddle shaft by use of a lug or bearing 52 upon the front end of the receptacle on which I pivot an eccentric block 53 having dwells 53'. The block supports the outer end of the frame structure or bearing supports. This eccentric block is operated by a handle 54 which is secured to the block shaft 55. By movement of the handle, different surfaces 53' of the block are brought into position beneath the extended frame structure, thereby supporting the frame, which carries the paddle shaft 2| and holds it securely in different positions to operate the paddle at a different height within the receptacle.

The raising or lowering of the paddle with relation to the tank and to the liquor in the tank is provided to give proper and efficient operation of the liquor when it is sprayed within the tank.

The bottom of the bafile. wall 20 is made hollow or concave as clearly shown in Figure 4 and the liquor dispensing paddle or spreader is positioned so that during the rotation thereof, the free ends of the outwardly positioned paddle blades will pass the free edge of the baffle wall 20 in close proximity thereto but spaced therefrom and so that the free ends of the scooping portion of the blades 38 will pass below the level of the etching liquor 56 and the free ends of the inwardly positioned paddle blades will pass above or clear such level. The effect of this arrangement of the parts is that the outwarldy positioned blades will dip into and pick up the etching liquor and the inwardly positioned paddle blades will blow air into the concavity of the wall 2|] and both the outwardly and the inwardly positioned paddle blades will throw the liquor into the cavity formed by the hollow bottom of the baffle wall 20 and discharge the air and liquor mixture between the blades and the free end of the baffle wall and project it in a finely divided flaring spray toward the rear wall IQ of the receptacle and against the plate as indicated by dash lines in Figure 4.

The provision of alternating radial positions of the paddle blades permits the etching liquor to flow into the path of the outer end portion of each rapidly rotating outwardly positioned paddle blade 51 following its dipping operation before the succeeding outwardly positioned paddle blade reaches the liquor and at the same time permits the employment of a sufficient number of blades for the projection of an efficient spray. Any liquor that falls down back of the outwardly positioned paddle blades 57 after being thrown thereby up against the baffle wall 20 drops upon the succeeding inwardly positioned paddle blade and is caught thereby and thrown up against the baflle 2G and out from under the same to be broken up and added to the spray. The advantage of outwardly and inwardly positioned paddle blades over paddle blades of the same positioning has been fully described in my patent mentioned above and it is therefore not considered to be necessary to describe the advantages of alternating inwardly and outwardly positioned blades over blades of the same radial positioning shown in my patent.

My invention is particularly adapted to the easy assemblage of the blades of Figure 7 into the different positioning slots of the disc-ewhich are clearly shown in Figures 5, a and 6.

It will be apparent that the placing of the tongues of the individual blades in the slots of the division walls upon the shaft and the clamping of all of the elements upon the shaft including the end discs and spacers by means of nuts 58 threaded upon the ends of the shaft 2| provides a simple and convenient method of assemblage which is also accurate and reliable in determining the desired amount of liquor to be scooped from the bottom of the receptacle and to be discharged into a spray against the wall [9 at the side of the receptacle.

In order that the level of the etching liquor 56 may be raised or lowered with relation to the paddle blades 24 and with a view to proper and efficient operation thereof I provide an overflow pipe 59 for the liquor which extends from the interior to the exterior of the receptacle. This pipe 59 extends through and is supported by a round tapered plug 60 which closes an opening in the forward Wall l8 of the receptacle and which may be turned to different positions of adjustment therein. The plug 60 may be formed of rubber or any other suitable material, and the pipe 59 extends therethrough eccentrically thereto so that the pipe may be raised or lowered to vary the maintained liquid level by turning the plug. The end portions of the pipe 59 are turned downwardly as illustrated and after the plug 50 has been adjusted the pipe 59 may be turned therein to adjust the downturned ends thereof into proper position.

The outer down-turned end of the pipe 59 dis charges into the upper end of a hollow tapered valve plug or stem 6| which is fitted to be turned in a valve body 62 connected to the receptacle l5 and having a passage 63 therein, in communication with the receptacle and normally closed by the plug.

The plug 6i has an opening 64 in one side thereof which may be turned into registry with the passage 63 for drawing the etching liquor from the receptacle and into a suitable receiver (not shown) below the plug El. When the etching liquor is introduced into the receptacle, the level of the liquor is governed by the position of the pipe 59 and the overflow of the liquor passes from the outer end of the pipe and into and through the hollow plug 6i down into the receiver beneath the same.

The lower rearward portion of the receptacle contains a plate-like support 65 for the plates to be etched. This support may be formed of stoneware or other suitable material and its upper portion is provided with a groove 66 for the reception of the lower portions of the plates to be etched. The forward edge of the support 65 abuts against a projection 67 on the bottom "5 of the receptacle .5

and the rearward edge of the support rests against suitably spaced parallel ribs 63 which project forwardly from rear wall IQ of the receptacle, and form abutments against which the upper edge portions of the plates to be etched may rest when the plates are placed upon the support 65 within the groove 65 thereof and tilted back against the ribs 68.

In Figure 4 I have shown a plate 69 to be etched resting upon the ribs 68, the ribs extending the full upright dimension of the interior of the receptacle or substantially so, to receive the upper edge portions of plates to be etched of varying sizes and support them in spaced relation to the rear wall l9 to provide passages between them for the down flow of etching liquor back of the plates.

The flaring spray of etching liquor delivered by the spraying device covers the entire rear wall It of the receptacle above the support, so that all parts of a plate to be etched of any size within the capacity of the machine will be reached and acted upon by the sprayed etching liquor. The purpose of providing the passageways between the ribs 68 is to permit the sprayed liquor which is projected toward the wall l9 above the plate to be etched to flow down back of the plate and prevent it from flowing down over the forward surface of the plate and thereby prevent the undercutting which occurs when the sprayed liquor 1 above the plate is directed to the forward surface thereof by the rear wall of the receptacle and thus permitted to flow down over the forward surface of the plate.

The top of the receptacle is normally closed by suitable cover plates and "H which rest upon ridges formed on the walls I], a slight distance below the top thereof. Plate H may be slid back up plate lll when access to the interior of the receptacle is desired for the introduction of etching liquor thereto and for the insertion and. removal of the plates to be etched and for other purposes.

The cover plate H is provided with a rib portion H close to its end nearest the rear of the tank wall. This rib portion is provided to stiffen the cover plate and in order to prevent breakage of the plate and the receptacle when the plate slides into closed position. The rib portion H is resilient in the direction of closing movement of the plate H.

The rear end ll of the cover plate Tl abuts against a rubber or other cushion material 72 which is placed in a recess 13 at the upper portion of the receptacle at its rear end (see Figure 8). I have found this rubber cushioning to act as an efiicient buffer to prevent breakage of the receptacle when the cover plate l! slides into closed position against the receptacle. Suitable drainage is provided at 14 between the cushion recess 13 and the receptacle.

The receptacle is provided with a passage leading from the upper portion of the interior thereof to the exterior thereof and located within this passage is a fan l6 which is carried and actuated by the power shaft of an electric motor 1! for the purpose of drawing a continuous stream of air into the receptacle [5 through the openings 42 and exhausting it through the passage 15 in accordance with the common practice in etching machines.

In Figures 9, 10, and 11 I have illustrated a modification in the construction of the paddle assemblage. In these figures I have shown the division wall discs 29' as being provided with a plurality of preferably circular recesses 29 into which the ends of longitudinally half circular blades 18 are inserted. When the blades 18 are placed in the recesses 29 of the discs 29 the blades can be turnedin the circular recesses until the blades are at the position desired. In this construction the ends of the blades are tongues and the recesses are cooperating grooves.

I have found the latter form of paddle construction to be advantageous when it is desired to use a special kind of etching liquor, such as ferric chloride solution.

These half circular sectional material blades of course may be made of any desired material, such as hard rubber, or a phenol-formaldehyde resin (for example, Bakelite), and can be used in liquid in which metal blades cannot be used. The structure used in assembling the modified form of paddle blade is in all other respects the same as that described in connection with Figures 1-8 inclusive and I have therefor given the same parts corresponding reference characters.

As will be seen in Figure 10, the scoop ends of the blades may be alternately set radially outwardly and radially inwardly by turning the blades in the slots. Radially outwardly positioned scoop ends are shown at 19, and radially inwardly positioned scoop ends at 80.

It will be evident that an important advantage of my invention is ready assembly of the paddle, as well as relatively fool-proof assembly, due to the positioning of the cooperating tongues and slots. Also, where a blade breaks, replacement is a very simple matter, and much more economical than where a whole paddle or a paddle section required replacement when a blade broke.

While I have shown the blades as half circular in Figures 9, 10 and 11, it will be understood that these blades may assume other shapes such for instance as the shape of the blade used in Figures 1-7 inclusive. If the blade of Figure 7 should be used it would not be necessary to employ the tongues 26 as the edges of the blade would fit in a slot in the division wall corresponding to the shape of the blade of Figure 7. It is not my intention to be limited in the use of different shaped blades.

In the form of Figures l-5 the central bores 35 of the discs or walls 25 are shown of the same diameter as the shaft 2|, the shaft centering the discs or walls 25 being intended to be made of etching-liquor-resistant materialsuch as stainless steel, while in the form of Figures 9-10 the disc bores 35' fit the outside of a sleeve 2| which sleeve centers the discs and being exposed to etching liquor should be of etching-liquor-resistant material, with the protected shaft 2! suit ably of less expensive material.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art to obtain all or part of the benefits of my invention without copying the structure shown and I therefore claim. all such in so far as they fall within the reasonable spirit and scope of my invention.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. In an etching machine paddle, a plurality of generally disc-like division walls having sets of slots in each of a plurality of walls, the slots of one set in each being adapted to position a blade radially inwardly and the slots of another set of each being adapted to position a blade radially outwardly, blades between the walls having tongues fitting removably into the slots in the walls, alternate blades around the paddle engaging the slots of one set and succeeding blades around the paddle engaging the walls in the slots of the other set and end clamping means for removably compressing the division walls and blades together in assembled relation, permitting removal and replacement of any blade upon releasing the compression means and releasing the tongue-and-slot connections of the blade with its supporting walls by relatively spreading the walls.

2. In a paddle for an etching machine, axially spaced division walls having sets of slots, the slots of one set being in radially outer position and the slots of the other set being in radially inner position, identical blades having their scoop ends circumferentially spaced around the paddle between the division walls and having tongues in the slots, the tongues of one blade on one side of the division wall fitting removably into the slots of one set and the tongues of the adjoining blade on the other side of the division wall fitting removably into the slots of the other set, and means for removably compressing the blades and division walls together in the assembled relation, permitting removal and replacement of any blade upon releasing the compression means and releasing the removable tongueand-slot connections of the blade with its supporting walls by relatively spreading the walls.

3. In an etching machine paddle, a shaft, a plurality of axially perforated division walls axially spaced along and movable along the shaft, and blades between and removably supported by the division walls making at their ends longitudinally overlapping interlocking connections with the division walls when the division walls are pressed together upon the intermediate walls and freely removable from between the division walls when the division walls are separated and means for removably pressing the division walls axially together upon the intermediate walls.

4. In a rotor for an etching machine, a shaft, a plurality of axially perforated generally axially spaced division walls movable along and sup ported upon the shaft, the said walls having toward one'another generally circular counterpart grooves at intervals around the circumference, blades having tongue portions which conform to parts of a circle fitting into the grooves, the blades extending from the grooves of one division wall to the counterpart grooves in the next division wall and means for removably compressing the blades and division walls together the grooves having arcuate eX- tensions greater than the arcuate extensions of the tongues received in the grooves permitting with temporary release of the said compression means adjustment of the blades along the grooves to adjust the radial extension of the blades from the shaft and permitting removal and replacement of any blade upon releasing the compression means and releasing the tongue-and-groove connections of the blade with its supporting walls by relatively spreading the walls.

5. In a paddle for an etching machine, a shaft, a plurality of axially perforated division Walls movable along and generally axially spaced along the shaft and the said walls having counterpart arcuate grooves toward one another at intervals around the circumference, paddle blades having arcuate ends received removably in the counterpart arcuate grooves of opposing Walls, said ends tting into the grooves along portions only of the groove length and said blades extending from one division wall to the next division wall, the alternate blades being angularly turned with respect to one another so that the scoop edges of the alternate blades are at respectively different radial positions, and means for removably compressing the division walls and blades together, the release of the compression means permitting arcuate adjustments of the blades in the counterpart slots or/and the removal and replacement of any blade during spread of the opposing walls at the blade ends.

6. In an etching machine paddle, a shaft, three paddle discs surrounding the shaft, each of the discs having longitudinally extending apertures laterally offset from the shaft and for removable driving connection with paddle blades and the middle disc having two sets of such apertures for connection at different points with blades, some at one end longitudinally of the shaft and some at the other end longitudinally of the shaft in order to form two complete paddles, paddle blades for the two paddles, the blades of one paddle connecting removably with one outer disc and with the middle disc in apertures of one set and the blades of the other paddle connecting removably with the other after disc and removably with the middle disc in the other set of apertures, tongues upon the blades passing removably into the apertures and by which the driving connection is made and clamp end devices upon the shaft whereby the discs are removably compressed upon the intermediate blades normally holding the discs and blades in their assembled position and permitting lateral removal and replacement of any blade during release of the compression and relative spread of the 0pposing discs at the blade ends.

7. A paddle for an etching machine comprising a shaft, a succession of axially perforated discs longitudinally slidable on the shaft, blades positioned between the disc, tongues on the blade ends, the discs having slots, receiving and fitting the tongues, the tongues and slots providing the blade at each end with removable tongue and slot driving connection with the discs and means for removably compressing the discs and the blades together in assembled relation by compression axially of the shaft permitting removal and replacement of any blade by releasing the compression means and then slightly spreading the discs at the blade ends to release the tongue and slot connection of the blade with the spread discs.

WILLIAM GUENST. 

